Using an ionized cluster beam (ICB) method, titanium oxide photocatalysts were prepared on porous Vycor silica glass (PVG) and activated carbon fibers (ACF), and their photocatalytic reactivities for the degradation of a-propanol diluted in water was investigated. Characterizations of these catalysts by means of SEM, XAFS, XRD, XPS and UV-Vis absorption techniques showed that the titanium oxide in transparent thin films could be formed on PVG and titanium oxide clusters could be deposited on the ACF UV irradiation of these catalysts in a diluted aqueous solution of 2-propanol or 1,2-dichloroethane led to the efficient decomposition of these reactants into CO2, H2O and HCl. The titanium oxide catalysts prepared on these porous materials exhibited higher photocatalytic reactivities than TiO2 powder and titanium oxide catalysts prepared by a conventional impregnation method. The present results have clearly shown that the ICE method is useful in the preparation of titanium oxide photocatalysts combined with porous supports such as PVG and ACF (C) 2000 Elsevier Science B.V. All rights reserved.